Gearing



Mar. 5, 1929. 1. A. MoGREw 1,703,942

GEARING Filed NOV. l7, 1927 '2 Sheets-Sheet 1 @Het ne q Mar. 5, 1929. J. A. MCGREW 1,703,942

u GEARING y Filed N0v.17, 192'? 2 shee-sheet 2 me/nto@ Patented Mar. 5, 1929.

unirse STATES PATENT OFFICE.

JOHN A. or ALBANY, NEW YORK, AssIeNOR To BETHLEHEM sri-:EL

l COMPANY, A CORPORATION or PENNSYLVANIA.

(HEARING.

Application led November 17, 1927. Serial No. 234,010.

with-either an auxiliary propulsion unit o1" l n interna-l combustion engine starting mechanisnrit 1s found to be sturdy, reliable and capable of operating through long periods of time with little attention. Its cxtreme simplicity, small bull; and low cost renders it suitable tor use with various other types ot' machines, as willebe apparent.

1n the accompanying drawings the invention is illustrated as' incorporated in each of the two above mentioned types otl mcchanical appliances butit will be understood that, without substantial alterationitl may be employed elsewhere or wherever itis found necessary to provide automatic means for 'temporarily establishing a positive drivingconnection between a power shaft and a driven shaft and automatically breaking such connection when the driven shatt attains a.- certain speed `of revolution or when the drive shaft ceases to rotate.

In addition, several views show the improved gearing Vslightly modied in various Ways'to suit various operating conditions. It Will be understood vhowever that these various forms are set forthby way ot example only, the invention not being limited strictly thereto' since` still additional-v forms may be designed or suggested Without departure from the spirit ot the invention.

Fig. 1 is a plan view of a motorized truck, or a truck upon which a steam driven auxiliary engineis-supported, my improved gearing being shown as applied-thereto for the purpose of temporarily connecting the auxiliary propulsion unit with one ot the truck supporting axles. .'Figure 2 is a section on line v'2 2 ot Figure 1. p

Figure 3 is a section taken on a line such as 2-2 of Figure 1 through that portion of the truck in which is located my improved gearing, but disclosing a form ol' gearing which differs slightly from that shown in Figure 2.

Figures 4 and 5 are views similar to Figure 8, by illustrating still further moditied forms of gear-ing.

Figure 6 is a section on line 6 6 ot Figure 5 but omitting portions of the gearing, the purpose being to illustrate principally the tumbler gear. 'Y

Figure 7 is a similar lvievv showing such modified :term ottumbler gear.

Figure 8 aside view'y of a portion of an internal comlnxstion-engine, showing the starting motor and gearing.

Figure 9 is an end view of the same.

Referring lirst to Figures 1 to 7 inclusive. The frame of the motorized truck is indicated at 10 and the load bearing axles at 12 'and 13 respectively. Upon the trame and l'axles is supported the propulsion unit for crank shaft 14 journaled in bearings 15 carried by the trame 10. The load bearing axle 13 is also journaled in bearings 15 carried by the frame. The crank shaft 14 has connected thereto a driving gear 16 which constantly meshes with a floating tumbler 17 movable to its ineshed and demeshed positions with respect to the driven gear 18 iixed on the load bearing axle 13. The tumbler gear 17 is of the floating type and has its axis positioned below the axes of the driving and driven gears 1G and 18 respectively. As shown in the drawings the floating tumbler gear-17 is in no way connectedby 'a pivotedframe or rocker. to the truck frame or to the driving or crank shaft 14, such tumbler gear being preferably of the full floating type and guided to meshed and demeshed positionsby means entirely independent of the shaftsY which it isadapted to connect, as for instance by stationary guide means 2O carried by the truck frame. i As shown in Figure 2, the guide means 2O extends from below the driving gear 1G up-v wardly toward the driven gear 18 and this guide means is so shaped and positioned that when the tumbler gear Yis in its demeshed position as shown in Figure 2, the teeth thereof will be only partially meshed with the teeth of the driving gear 16. The `guide means is so formed as to guide the tumbler gear 17, when the latter is moved toward the driven gear, until the teeth thereof are partially enmeshed with the teeth of the driven gear 18 whereupon, due to.tooth pressure alone, the tumbler gear. will be thrown completely into mesh with the driving and driven gears 16 and 18 respectively and will be lifted out `of contact with the guide means 20.

In order to assure movement of the tumbler gear 17 in a meshing direction with respect to the driven gear 18 when the driving gear 16 is moved inthe direction of the arrow with thatA form of the invention dis, closed in Figures 1 and 2, I provide meant to positively prevent idle rotation or spinI ning of the tumbler gearwhen the drive gear initially starts to rotate. this function I provide an eseapement or detent device 21 pivoted at 22 upon the upwardly extending lugs 23-carried by the bottom of the gear case 24 of the frame, the esf` capement 21 being provided with teeth 25 and 2G adapted to engage respectively between the teeth of the tumbler gear 17.

i t With the tumbler gear 17 -in its demeshed `position, as shown in Figure 2, the tooth 25 of the eseapement projects between two adjacent teeth of the tumbler, the forward tooth 26 of the escapement being out of con- 'tact with the teeth of the gear. Upon actuatio of the driving gear in the direction of the arrow the tumbler moves forwardly,

the tooth 25 preventing rotation or spinning ofthe tumbler -gear 17' idly about its axis,

acting somewhat in the lmanner of a rack tooth, and causing the tumbler'gear 17 to` move abruptly toward the driven gear. As the tumbler also rests against the guide means 20, it is guided thereby directly in a meshing direction. As it moves the escapement 21 is caused to pivot thereby about its axis 22 thereby @swinging its forward tooth 26 upwardly into the path of movement of For performing'v weas-aa enmeshment of the tumbler with both driving and driven gears follows.

In the form of the invention illustratedin Figures 1 and 2 the guide means takes the form of upwardly curved spaced surfacesl provided by stationary structures arranged within the gear ca se 24. 1f desiredl may provide meaiis'for-preventing undue crowding of the tumbler 'gear in between the driving and driven gears. .Such crowding may be effectively prevented by providing gears 16, `17 yand' l@ with shrouds such as 16, 17a and 18W extending to their pitch circles. These `shrouds have rolling contact when the gears are completely meshed.

In'thefforms'of my invention shown in .Figures and4, the tumbler gear 1 7 is provided lwith-trunnions adapted to move on suitable stationary guides for the purpose of guiding the tumblerA 'gear in ts movements. In Figure 3 I show the tu'A nbler gear `17 as having trunnions 27 which extend into slots.28 carried byvstructure 29 which last mentioned structure is supported upon thev ltruck frame. The slots 28 are arranged be-- lowA the axes of the drivin and driven gears 16 and 18-which slots incline forwardly and upwardly from itslower end toward the driven gear 18. The lower ends of theslots 28 defining the lower, limit otr' the movement of the tumbler gear17.v The upper ends 30 of slots 28 form bearings for the trunnionsK 27 when the tumbler gear is in its uppermost positions that is,when the trunnions 27 have reached the upper-,ends of slots 28 the. tumbler gear 1-7 is in full mesh with the driving and driven gears.

When the tumbler gear-17 is in its demeshed position, a ldetent 21 cooperates the teeth of the, tumbler gear, between tm therewith in the same manner as has already vof the teeth of which it projects as the tumbler` gear moves thereacross, to prevent.;

spinning' or idle rotation of the tumbler after itleaves the rearward tooth 25. escapement is preferably so designed that' the forward tooth 26 thereof shall assure*- so arranged that when the tumbler gear, is

in its demeshed position the teeth thereof The been described in connection .with the gearing shown in vFigures 1 and 2. The slots "28 can be Soarranged that, when the tumbler 17 is in its demeshed position the teeth thereof are only partially meshe'd with the driving gear 16 and the slots 28 extend upwardly toward the driven gear seas to assure that the teeth of the tumbler gear shall be partially enmeshed with the driven gear whereupon, due to toothpressure, the tumbler gear 17 will be completely enmeshed with the driving gear and with thedriven gear, this resultant enmeshment movement of the tumbler gear causing its trunnions to rest against the upper ends of the slots. With this form of gearing it is unnecessary` to provide the gears with shrouds, the bearing portions 30 of the slots 28 and the trungearing of Figure 3.

different in that they are Wider. The lower s lends of the these slots serve to supporttrunnions'27 when the tumbler gear 17 is in-l operative. Thetunnions have suiiicient play in the slots 31 and the latter are so designed that, when the tumbler gear 17 is in its demeshed position, the teeth of such tumbler gear are only partially meshed with the teeth of the driving gear 16; while the slots 31 serve to lguide the tumbler gear toward the driven gear 18 until the tumbler gear partially meshes with the teeth of such driven gear, whereupon, at that instant, the

tumbler gear will be partially meshed both with the driving gear 16 and the driven gear 18. The slots 3L provide sufficient play` for the trunnions 27 so that, when this condition of partial enmeshment of the tumbler gear with both gears takes place, the tumbler gear will then be complet-ely meshed with both the driving and with the driven gears due wholly to tooth pressure. In order to positively assure translatory movement of the pinion 17 in a meshing direction, I provide a detent 21 for cooperation with the tumbler gear 17 in Figure 4, such detent functioning in the'manner already set forth in the description of the operation of the Since the trunnions 27 do not fit bearing portions to resist crowding of the tumbler gear 17 with respect to the drivinggear 16 and the driven gear 18, all of suchv gears are preferably shrouded as in the form of gearing shown in Fig. 2.

In the embodiment of my invention shown in Figs. 5 and 6, the' shrouded portions 32 of the tumbler gear 17 are made relatively long and cooperate with lateral guides 33 carried by the-trucklframe structure.` These guides areA formedwith portions v34 at their lower ends which cooperate to hold the iioating tumbler gear 17 in its demeshed position, as indicated in dotted lines inFigure 5. The guides 33 extend upwardly toward uthe driven gear 18 so that the tumbler gear 17 may be brought into meshing relation with respect thereto. The guide members 33 are so shaped thatthe tumbler gear 17 shall be brought-to a position where it partially meshes with the driving gear 16 and` With the driven gear 18, whereupon the tooth pressure results in the tumbler gear being brought into complete mesh with the driving and with the driven gears, Ythe shrouded members 32 carried by the tumbler gear cooperating with shrouded members 35 y and 36 on the driving gear 16 and the driven gear 18, respectively, to limit or prevent crowding. In this form of my invention,l friction of the shrouded members 32 upon the guides 33 is relied upon to cause the tumbler gear 17 to travel upwardly of the guides toward the driven gear 18 when the driving gear 1G is actuated.

In the form of my invention shown in Figure 7, I provide friction surfaces 38I arranged beyond the shrouds 32 which may be smaller in diameter than the latter, the friction surfaces 38 and the complementary surfaces on the guides being roughened in any suitable manner to assure that the tumblei` gear 17 shall be rolled up the guides 33 to mesh with the driven gear.

The novel gearing may be readily incorporated in an internal combustion engine starting mechanism and in Figures 8 and 9 such .ainechanism is disclosed. The tly wheel of the engine is indicated at 40, and is shown to be toothed, as at 41. A starting motor of usual type is indicated at and thev starting pinion at 43. The tumbler gear 441 is provided with trunnions a5 which run on spaced' curved guide surfaces 46 formed on the tops of upright lianges 417 of the horizontally extending channel member 48. The action of thetumbler gear is substantially the same as in lthe case of the gears shown in the preceding iigurcs but it has been found in4 actual practice that. the use of detents or friction surfaces on the trunnions is unnecessary, the rapidly spinning starting Vpinion throwing the tumbler gear into mesh immediately and yWithout difficulty, although no means for retarding its spinning is provided.

As soon as the internal combustion engine starts the fly wheel of course throws out the tumbler because its peripheral speed is greater than that of the starting pinion, and the current supply to the starting motor is interrupted. The motor 4t2 and guide L18 are suitably secured to the frameV upon which the enginev is supported. From the foregoing, it will be apparent that I have devised tumbler gearing which is characterized'by the presence lof a tumbler gear located belowv the of the driving and driven gears'in combination with guide means extending upwardly toward the driven gear, so that, when the driving gear is inactive, gravity is eiiective `to .maintain the tumbler gear out of meshv with the driven gearl Also, since the tumbler gear is iloating tumbler gear below theJ driving and the driven gears, it is'assured that more space may be provided at the upper side of the truck for certain of the truck parts. This is also true, of course, where the gear- 'ing is used in connection with an automo bile engine starting mechanism.

lVhile I have shown my invention in a plurality of forms, it will be obvious to'those skilled inthe art that itis not so limited, but is susceptible of various other changes and modifications without departing from the spirit' thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or' as are speciiically set forth in the appended claims.

Having thus described' the invention, what is claimed as new and vdesired to be secured by Letters Patent is:

1. Gearing comprising in combination, a driving gear, a driven gear, a tumbler gear in constant mesh 'with the drive gear and movable into and out of mesh with the driven,.ffear, andfmeans for' guiding the tumbler to a position of partial enmeshment With the driven gear when the driving gear is actuated, whereupon the `tumbler and driven gears are, completely meshed due to tooth pressures and the tumbler withdrawn from the guide means.

2. Gearing comprising in combination, a frame, driving and driven shafts mounted in the frame, driving and driven gears earried by said shafts respectively,l a tumbler gear havingits axis arranged below the axes of the driving and driven gears and in con- -stant mesh with the driving gear, said tumbler being movable into and out of mesh with the driven gear, means carried by the frame for guiding the tumbler gear upwardly toward the driven gear when the tumbler gear moves in a direction to mesh with the driven gear and to receive the tumbler gear when it moves out of mesh with the driven gear, said guide means being constructed to. guide the tumbler gear to a position of partial enmeshment with the driven gear so that the. two last mentioned gears are fully meshed by tooth pressures and the tumbler is removed from the guide means.

8. The .combination set forth in claim 2 in which means is provided in association with the tumbler gear for bringing about a movement thereof toward the driven gear upon activation of the drive gear.

4. In a gearing, the combination with` driving, driven and tumbler ygears of means for supporting the tumbler gear at all times in mesh with the driving gear and for guiding` it toward the driven gear y when the driving gear is actuated, the arrangement being such that the complete meshing of the tumbler and driven gears is effected by tooth pressure, the tumbler gear being comgear A is i pletely` withdrawn from the supporting and guiding means when in full mesh lwith the. driven gear.

5. The combination set forth in claim a in which the supporting means is positioned 'beneath the driving gear and has a portion 8. In a gearing, the combination with'- driving, driven and tumbler gears of means for supporting the tumbler gear at all times in mesh with the driving gear and for guiding it toward .thedriven gear when the driv- .ing gear is actuated, the arrangement being such lthat the' complete meshing of the tumbler and driven gears is effected by tooth pressure, the tumbler. gear being completely -withdrzmfirfrom the supporting and guiding .means when in full mesh withthe driven gear, and means for initially retarding rotation of the tumbler gear about its axis upon initial movement of the driving gear bler gear toward the driven gear when the driving gear is actuated.

k9. The combination set forth in claim 8, in which said last mentioned means is a friction means. Y

10. The combination' set forth in claim 8 in whiehsaid' last mentioned means friction ally retards rotation of the tumbler about\ its axis prior to the-tiine when the tumbler is in mesh with the driven gear, which means becomes ineffective upon meshing of the tumbler and driven gears.

l1. In a gear, the combination with drive, driven and tumbler gears of means for supporting the tumbler gear at all times in mesh with the driving gear and forl guiding it toward -the driven gear when the driving gear is actuated, said supporting means comprising spacedy parallel" members having guide surfaces. formed thereon and the turnbler gear having cylindrical end portions on each side of the central toothed. lportion 'for insuring prompt`movement of the tumadapted 'to roll on said guide surfaces, the i `12. In a gear, the combination with driving, driven and tumbler gears of means vforA pressure, the tumbler gear being completely Withdrawn from the supporting and guiding 10 means when in full mesh with the driven vgear, and all of said gearsbeing provided with shrouds for the purpose set forth.

In ,testimony whereof I hereunoaix my signature. A

JOHN A. MGGREW. 

